Fire alarm switch



March 20, 1951 LEVY 2,545,854

FIRE ALARM SWITCH Filed March 5, 1950 Patented Mar. 20, 1951 UNITEDSTATES PATENT OFFICE 3 Claims.

My invention relates to a new and useful fire alarm station such as isused inside of buildings to cause an alarm or signal to result from thebreaking of a fragile front panel.

An object of the invention is to improve the construction of devices ofthis character which will be exceedingly simple, strong and durableandincluding the elements of an electric circuit closer or switchcapable of positively completing an electric circuit under certainconditions.

Another object of the present invention is to produce a circuitcloser'for a fire alarm station including a stationary contact memberand a gaged, under certain conditions, by a strong single strand springwire movable contact member having one end secured at the bottom of thechamber and the other end projecting into a cavity behind the stationarycontact member, and said approximately equal to the thickness of thefragile panel 8, such as glass, which is seated on said shoulder andheld in place by securing means l 9. The securing means may be anyappropriate movable contact member having an elbow intermediate its endsto be engaged by a fragile holding panel for normally retaining themovable contact in a depressed position.

With the above and other objects in view this invention consists of thedetails of construction and combination of elements hereinafter setforth and then designated by the claims.

In order that those skilled in the art to which this inventionappertains may understand how to make and use the same I will describeits construction in detail referring by numerals to the accompanyingdrawing, in which-- Fig. 1 is a front elevation of a complete fire alarmstation constructed in accordance with my invention.

Fig.' 2 is a section on the line 22 of Fig. 1 showing the movable springcontact depressed.

Fig. 3 is a similar view with the fragile front panel removed, as afterbeing broken, illustrating the movable spring contact projectedforwardly by its inherent resiliency to complete the electric structuredetachably fastened to the body 5 and overlapping the edge of thefragile panel. As illustrative of ,a form of panel securing means I haveshown rings or grommets l6 large enough for the perimetersto overlap theedge of the panel or overlie the shoulder I while the center holes aredisposed beyond the edges of the shoulder and panel for the reception ofscrews ll threaded into the body 5.

The-back of the body may have a compartment I2 formed therein inalignment with the chamber 6 to provide a partition l3.

In the bottom of the chamber 6 or in the forward face of the partitionis formed a cavity l4 which is bridg'ed'by a stationary contact member!5 preferably in the form -of a plate of good electric conductivitysecurely and positively fastened in place by screws l6 and H projectedthrough the back of the body, especially the partition l3 and threadedinto stationary contact member to hold it fast against the bottom of thechamber 5. The screw I! is of suflici'ent length to accommodate a'washerl8 and a conductor I9 of an electric alarm system including a signalmeans *front face of the anchor plate 20a sufiicient distance toaccommodate the eye 25, Fig. 4, of the stiff, strong, single strandspring wire movable contact member 26 and a nut 21.

The movable contact member 26, as stated above, is formed from strongspring wire fashioned to provide the eye 25 at one end from which thewire extends outwardly and then bent back as a U-shaped loop 28 to oneside of said eye with the branches of said loop in the same plane as thecoil of the eye. the wire is bent outward and then inward to provide anelbow 29, the legs of which diverge, and finally the end of said wire isbent to lie in a plane parallel with the plane of the branches of theU-shaped loop 28, to from the contact terminal 30.

The movable contact member 26 is fastened to From the U-shaped loop theanchor plate 20 by placing the eye 25 over the screw 2i and screwing thenut 21 in position on said screw 2|, with the contact terminal'end 3Uprojecting into the cavity [4 and in back of the stationary contactmember. The cavity id is of sufficient depth to allow a limitedoscillatory movement of the contact terminal end of the movable contactmember 26 whereby said end may be moved out of engagement with thestationary contact member i5 under certain cnditions. Also, the elbow 29is of such dimensions that when the contact terminal end 30 of themovable contact member is in engagement with the under side of thestationary member l5, Fig. 3, said elbow 29 projects outside of theplane of the shoulder 1. Therefore, when the elbow is in or inside ofthe plane of the shoulder, as when retracted by the panel 8 resting onsaid shoulder I, the contact terminal end 3!! will be out of engagementwith the stationary contact member l5, Fig. 2.

For convenience, a hook 3| may be fastened to the body 5, as at one sidethereof, and one end of a fiexible means 32, such as a chain, alsosecured to said body 5, as by the hook, and to the free end of saidflexible means is attached a hammer 33,-ordinarily suspended from thehook and used for breaking the fragile panel 8.

In order to identify the device as a fire alarm station, a paper tag 34may be placed in back of the fragile panel 8, said tag having the wordFire or equivalent information or additional wording delineated thereonor the desired information and directions depicted in any other suitablemanner.

In practice, the device is completely assembled including the mountingof the fragile panel so that the movable spring contact member isdepressed or retracted, as illustrated in Figs. 1 and 2. When thestation is installed, the wires l9 and 24 are connected in a circuitincluding a source of electricity and an alarm device, such as a bell,which is the usual custom and the body fastened to a support, such as awall, by fastening devices, such as screws, projected through the holes35 and into the support.

Whenever it is necessary or desirable to give an alarm the fragile panel8 is broken by striking it with any suitable instrument, such as thehammer member 33. This will release the pressure on the movable springcontact 26 so that it can snap outwardly whereby the terminal contactend 30 will engage the rigid stationary contact member l withconsiderable force to immediately produce an excellent unwaveringelectrical connection between the two contact members.

Of course I do not wish to be limited to the exact details ofconstruction herein shown and described as these may be varied withinthe scope of the appended claims without departing from the spirit of myinvention.

Having described my invention, what I claim as new and useful is:

1. A fire alarm station comprising a body having a chamber in the frontthereof with a cavity in the bottom of said chamber, a rigid stationarycontact member imposed on the bottom of said chamber and bridging aportion of said cavity. means projected through the back of the body tosecure the stationary contact in place and function as an electricalconductor, an electrical conductive anchor plate on the bottom of thechamber in spaced relation to the Stationary 00 1- tact member, amovable contact member having one end mounted on the anchor plate, meansprojected through the back of the body to fasten said anchor plate andthe contiguous end of the movable contact member in place and a portionof said fastening means functioning as an e1ectric conductor, saidmovable contact member consisting of a stiff resilient section of wirefashioned to provide an eye at the anchored end from which the wireextends outwardly and then back as a U-shaped loop to one side of saideye with the branches of said loop in the same plane as the coil of theeye and the wire then bent outward and inward to form an elbow extendingto the open end of the chamber and finally projecting in endwisealignment with one of the branches of the U-shaped loop as a freeterminal contact end extending into the cavity in back of the stationarycontact member, a fragile panel, and means to secure said panel to thebody across the open end of the chamber, said panel engaging the elbowto press the terminal contact end out of engagement with the stationarycontact member, said movable contact member being released upon breakingof the panel whereby the terminal contact end engages the stationarycontact member to complete an electric circuit.

2. The fire alarm station according to claim 1 wherein the body isprovided with a recessed shoulder surrounding the open end of thechamber against which the fragile panel rests and the means to securesaid panel in place consists of rings held in place by screws projectedthrough said rings and into the body with por tions of the ringsoverlapping the rim of the panel.

3. As an article of manufacture, a fire alarm station comprising a bodyhaving a chamber in the front thereof with a recessed shouldersurrounding the open end of said chamber, a rigid stationary contactmember secured to the body within the chamber and spaced from the bottomof said chamber, a stiff resilient movable contact member consisting ofa section of wire fashioned to provide an eye at one end and a U- shapedloop to one side of said eye and an offset elbow at right angles to theloop and a terminal contact end, said movable contact member being fixedon the bottom of the chamber by means of the eye with the terminalcontact end positioned in back of the stationary memher and the elbowprojecting towards the open end of the chamber and extending beyond theshoulder when the terminal contact end is in engagement with thestationary contact member, a fragile panel seated on the shoulder andengaging the elbow of the movable contact member to depress the latterto normally hold the terminal contact end out of engagement with thestationary contact member, means to secure the panel in place, and meansto connect the movable and stationary contact members with oppositesides of an electric circuit.

MORRIS LEVY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 992,633 Auth May 16, 19112,030,799 Parsons l Feb. 11, 1936

